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Propagation behavior in rectangular metallic waveguide periodically loaded with single negative metamaterial slabs
No full textThis paper focused on propagation characteristics of a single mode supporting waveguide enclosed by metallic sidewalls periodically loaded with lossless single negative (SNG) metamaterial slabs along axial direction. The gap between two successive SNG slabs is filled with a double positive (DPS) material. For the analysis, the periodic structure is assumed having symmetric unit cell (UC) and simplified as a two-port network which is one-half of the symmetric UC. Scattering parameters (S-parameters) are defined by even/odd mode analysis of the symmetric UC, and then the total S-parameters are calculated by solving the cascade connection of N unit cells. Eigenvalue equations are also obtained to explicit the solutions of band edge and pass/stopband diagrams in the microwave regime. Since a SNG can be either epsilon-negative (ENG) or mu-negative (MNG), S-parameters and dispersion behavior are illustrated with numerical examples and discussed for each periodic structure constructed with ENG or MNG slabs
New AB3-type porphyrins with piperidine and morpholine motifs; synthesis and photo-physicochemical and biological properties
No full textIn this study, new unsymmetrical meso-tetraaryl AB(3)-type porphyrins 1 and 2 were successfully synthesized by the reaction of p-bromobenzaldehyde and p-hydroxybenzaldehyde with pyrrole in propionic acid. AB(3)-type porphyrin building blocks with hydroxyl functionality (1 and 2) were further used to generate both covalently linked metal free and Zn(II) porphyrins 3-6 having piperidine and morpholine heterocyclic units. These novel compounds were characterized by using H-1 NMR, C-13 NMR, FT-IR and MALDI-TOF spectrophotometry. The photophysical and photochemical properties of compounds 1-6 were investigated by employing UV-vis absorption and fluorescence emission spectroscopy in tetrahydrofuran (THF). From the view of biological properties, the antioxidant capacities of porphyrins were determined by using DPPH radical scavenging activity and 2 was determined as the most potent porphyrin analog with a value of 98.42% at 200 mg L-1. All the targeted compounds displayed significant DNA nuclease activity. In addition, the antimicrobial potential of compounds 1-6 was also investigated by a micro-dilution process and 2 was found to be the most effective candidate against the tested microbial strains. The newly synthesized porphyrins also showed 100% microbial cell viability inhibition against E. coli at all examined concentrations. In terms of biofilm inhibition activity, the best results for the maximum photodynamic antimicrobial biofilm inhibition of S. aureus and P. aeruginosa were obtained by compound 2 with the values of 99.75% and 93.39%, respectively
A biocompatible, eco-friendly, and high-performance triboelectric nanogenerator based on sepiolite, bentonite, and kaolin decorated chitosan composite film
No full textRecent advancements in triboelectric nanogenerators (TENGs) have primarily focused on improving power conversion and generation efficiency. However, challenges still exist in developing TENGs that are affordable and biocompatible. Chitosan, an abundant natural biopolymer derived from marine crustacean shells, and natural clays offer exciting possibilities for developing cost-effective and biodegradable TENG applications. In this study, we present the development of biocompatible and eco-friendly TENGs by incorporating clay-based compounds as natural fillers into chitosan. To construct chitosan/clay-based biocomposite TENGs, we have introduced sepio-lite, bentonite, and kaolin, as natural additives, into the chitosan biopolymer matrix. Decorating chitosan with natural clays improves the triboelectric properties of the TENGs, which in turn enhances the output voltage and significantly boosts the electric power density. Chitosan-based TENGs with 3 wt% sepiolite, 1 wt% bentonite, and 1 wt% kaolin demonstrate open circuit voltages of 863, 996, and 963 V, respectively. Moreover, when compared to pure chitosan-based TENG, the chitosan-based TENGs with 3 wt% sepiolite, 1 wt% bentonite, and 1 wt% kaolin show a maximum output peak power increase of 19, 54.4, and 32.6%, respectively. At 1.1 M omega load resistance, the maximum peak electric power densities of 20.4, 26.5, and 22.8 W/m2 are reached for chitosan-based TENGs with 3 wt% sepiolite, 1 wt% bentonite, and 1 wt% kaolin, respectively. Furthermore, we analyzed the surface potential, morphology, roughness, and dielectric constant of chitosan/clay composites to understand the relationship between them and electrical performance. The results demonstrate that the output performances of the chitosan/clay-based TENGs are quite high. TENGs made of biocompatible materials may not only pave the way for the production of environmentally friendly, cost-effective, and efficient TENGs for self-powered nano -systems and biomedical devices but may also shed light on new technologies utilizing natural materials
Rethinking the design studio curriculum through adaptive and transformative strategies and acts: Cross-cultural reflections
No full textThis study presents and reflects on the experiences of three design studios in various undergraduate programmes in China, Turkey and Colombia during the COVID-19 pandemic. The study identifies adaptive and transformative strategies and acts implemented in these scenarios to respond to rapidly changing circum-stances. Consequently, this study is aimed at educators and administrators in design programmes, design researchers and the wider design and higher education (HE) communities. A descriptive multi-case study design was applied to describe several instances of a contemporary phenomenon within its natural environment. In these case studies, the authors present and reflect on their teaching experiences before, during and after the pandemic. The authors identify the following adaptive and transformative strategies and acts that contributed to creating resilient, sustainable and inclusive learning environments during the pandemic: (1) rede-signing the curriculum as an emergent phenomenon; (2) adapting the project brief and adjusting learning expectations; (3) expanding the instructor’s role in the studio; (4) renegotiating the boundaries between students and instructors; (5) increasing awareness about students’ mental health and well-being; (6) adopting new tools, materials and techniques, and adapting the existing ones; (7) imple-menting new methods for communicating with the students. This article contrib-utes to the existing discussions about the future of design education. The findings can help plan future design curricula that are adaptable, flexible and responsive to change. Such curricula can better address different student needs, whose educational experiences can have longer-lasting effects through their contributions to society upon graduation. In this cross-disciplinary and cross-cultural study, authors use resilience, sustainability and inclusivity as lenses to analyse their respective contexts. Even though these categories have been used independently or in combination to approach educational phenomena in the past, this is the first study that applies them in the context of design studio education. © 2023 Intellect Ltd Article. English language
A Review of Recent Innovations in Remote Health Monitoring
No full textThe development of remote health monitoring systems has focused on enhancing healthcare services' efficiency and quality, particularly in chronic disease management and elderly care. These systems employ a range of sensors and wearable devices to track patients' health status and offer real-time feedback to healthcare providers. This facilitates prompt interventions and reduces hospitalization rates. The aim of this study is to explore the latest developments in the realm of remote health monitoring systems. In this paper, we explore a wide range of domains, spanning antenna designs, small implantable antennas, on-body wearable solutions, and adaptable detection and imaging systems. Our research also delves into the methodological approaches used in monitoring systems, including the analysis of channel characteristics, advancements in wireless capsule endoscopy, and insightful investigations into sensing and imaging techniques. These advancements hold the potential to improve the accuracy and efficiency of monitoring, ultimately contributing to enhanced health outcomes for patients
Classification of Resampled Pediatric Epilepsy EEG Data Using Artificial Neural Networks with Discrete Fourier Transforms
No full textEpilepsy is a neurological disorder commonly observed in children. Currently, electroencephalography (EEG) is widely used as the most important diagnostic method for epilepsy in medical practice. The diagnosis of epilepsy in pediatric patients is challenging due to their high level of activity and incomplete brain development. In this study, data sampled at 256 Hz were obtained from patients between the ages of 7-12, collected by Boston Children's Hospital. First, the image intervals that contain seizure waves were identified in the datasets, and the discrete-time Fourier transform (DFT) was applied. The amplitude-frequency features of the frequency spectrum in seizure and nonseizure states were obtained, and patients were classified for seizure detection using a multilayer perceptron (MLP) based on an artificial neural network (ANN) architecture. In the next step, the EEG signals were resampled at low frequencies, and the same analyses were repeated to minimise the disadvantages of limiting factors such as storage space and processing power, resulting in reduced storage space usage and more efficient performance
BİSİKLET PAYLAŞIM SİSTEMLERİNDE KENETLENME İSTASYONU YER SEÇİMİ İÇİN BİR ÇKKV MODELİ
No full textBisikletler, sağlık, ekonomik, çevresel olumlu etkileri nedeniyle birçok ülkede ulaşım aracı olarak da kullanılmaktadırlar. Ayrıca, paylaşım ekonomisinin başlıca örnekleri arasında bisiklet paylaşım sistemleri gelmektedir. Bu sistemler farklı istasyonlarda bulunan bisikletleri, kullanıcıların istedikleri sürelerde kullanılabilmesine izin verirken; trafik ve hava kirliliğinin azaltılmasını, bisiklet sahibi olmayanların uygun ve hesaplı bir ulaşım aracına erişmelerini sağlar. Faydalarının yanı sıra, bisiklet paylaşım sistemleri çeşitli zorluklarla da karşılaşmaktadır. Kenetlenme istasyonlarının doğru konumlandırılmaması bazı istasyonlarda bisiklet eksikliğine, bazı istasyonlarda ise boş kenetleme ünitesi eksikliğine neden olmaktadır. Bu durum sistemin bütününün verimliliğine olumsuz etki etmektedir. Bu çalışmada, Coğrafi Bilgi Sistemleri (CBS) ve çok kriterli karar verme yöntemlerini bütünleşik olarak kullanıp, sisteme eklenecek yeni istasyonların konumlarını belirleyen bir model önerilmektedir. Bu modelde öncelikle olurlu bölgeler CBS uygulaması desteği ile belirlenmiştir. CBS girdileri, İBB’den temin edilen verilerin yanı sıra açık kaynak veri bankalarından derlenmiştir. Olurlu bölgelerin belirlenmesinde Analitik Hiyerarşi Süreci kullanılarak kriterler ağırlıklandırılmış, belirlenen bu ağırlıklar ile ısı haritaları oluşturulmuştur. Kriter ağırlıklandırılmasında ve olurlu bölgedeki alternatifler arasından en iyiyi belirlemede paydaşların oluşturduğu bir karar verici grubuna başvurulmuştur. Önerilen bu melez yöntem var olan bisiklet istasyonlarını da dikkate alıp, yeni istasyonların en uygun yerlere kurulmasını amaçlamakta ve sistemin her yeni istasyonla birlikte etkinliği ve verimliliğini arttırmayı hedeflemektedir
Exploring the magnetic dipole moments of TQQqs and TQQss states in the framework of QCD light-cone sum rules
No full textMotivated by the recent observation of the tetraquark T-cc(+), we investigate the magnetic dipole moments of the possible single and double strange partners, T-QQqs and T-QQss, with the spin-parity J(P) = 1(+) by means of the QCD light-cone sum rules. To this end, we model these states as diquark-antidiquark states with different organizations and interpolating currents. The results of magnetic dipole moments obtained using different diquark-antidiquark structures differ from each other, considerably. The magnetic dipole moment is the leading-order response of a bound system to a soft external magnetic field. Therefore, it provides an excellent platform for investigation of the inner structures of hadrons governed by the quark-gluon dynamics of QCD.Iran Science Elites Federation (Saramadan) [ISEF/M/401385]K. Azizi is grateful to Iran Science Elites Federation (Saramadan) for the partial financial support provided under the grant number ISEF/M/401385
Impact of organizational culture on big data analytics capabilities
No full textLisansüstü Eğitim Enstitüsü, İşletme Ana Bilim Dalıİşletmeler özellikle son birkaç yıldır, rekabet avantajı sağlamak ve rakiplerinden bir adım öne geçmek için büyük veriye olan ilgilerini artırmışlardır. Gelişen teknoloji ile giderek önem kazanan büyük veri analitiği uygulamalarının, yakın gelecekte pazar dinamiklerini şekillendiren ve işletmelerin karlılık durumunu etkileyen en önemli faktörlerden birisi olması kaçınılmazdır. Örgüt kültürü, varsayımları, değerleri, normları ve sembolleri aracılığıyla bir örgütün strateji, yapı ve süreçler gibi çeşitli yönleri üzerinde güçlü bir etkiye sahiptir (Alharthi ve diğerleri, 2017). Birçok kuruluşun büyük veri projelerinde, büyük veri yeteneklerinden yararlanmak için doğru teknolojik araçlara sahip olmadığından başarısızlık yaşadığı görüşü bulunmaktadır. Ancak, son zamanlarda büyük veri projelerinin genellikle başarısız olmasının nedenlerinin veri teknolojisinden ziyade örgüt kültürü ile ilgili olduğunu belirtilmektedir (Shamim ve diğerleri, 2020; LaValle ve diğerleri, 2014). Bu tez çalışmasının amacı örgüt kültürü boyutlarının büyük veri analitiği yeteneklerini ne ölçüde etkilediğinin araştırılmasıdır. Araştırma, Cameron ve Quinn'in (2006) ele aldığı dört örgüt kültürü tipinin, işletmelerde büyük veri analitiği yeteneklerinden yararlanırken söz konusu olabilecek muhtemel etkileri incelemektedir. Araştırmada veriler anket yöntemi ile toplanmıştır ve 2022 yılında büyük veri kullanan uzman ve yöneticiler tarafından cevaplanmıştır. Araştırmada; örgüt kültürü algısı ile büyük veri analitiği yetenekleri arasında yüksek düzeyli, pozitif ve anlamlı bir ilişki tespit edilmiştir.In recent years, businesses have been increasing their interest in big data to gain a competitive advantage and stay ahead of their competitors. The growing importance of big data analytics applications, driven by advancing technology, is inevitable as it becomes one of the most significant factors shaping market dynamics and impacting the profitability of businesses. Organizational culture has a strong impact on various aspects of an organization, such as its strategy, structure, and processes, through its assumptions, values, norms, and symbols (Alharthi et al., 2017). There is a perception that many organizations fail in their big data projects because they lack the right technological tools to leverage the capabilities of big data. However, it has been recently suggested that the reasons for the frequent failure of big data projects are more related to organizational culture than data technology (Shamim et al., 2020; LaValle et al., 2014). The aim of this thesis study is to investigate the extent to which dimensions of organizational culture influence big data analytics capabilities. The research examines the potential effects of the four types of organizational culture addressed by Cameron and Quinn (2006) on the utilization of big data analytics capabilities in businesses. Data for the research was collected through a survey method and was answered by experts and managers who utilized big data in 2022. The study identified a significant, positive, and high-level relationship between the perception of organizational culture and big data analytics capabilities
An Explorative Analysis of Tweets Sentiments for Investment Decision in Stock Markets
No full textNowadays lots of researches report that positive or negative social media posts have significant effects on stock market returns. In particular, as well as long-term effects, it may be important to identify the short-term effects of public opinions on the stock market. Unfortunately, the number of studies conducted in this context for Turkey is very limited. Therefore, this study investigates the relationship between Turkish tweets and the trend of Bist30 index returns for short-term analysis. Correlation analysis is a statistical method used to measure the strength and direction of relationship between two variables. The existence of a short-term correlation between sentiments of financial tweets and the stock market returns may be an indicator that social media can be used as a resource to predict the sudden changes of stock markets returns. In this study, the correlation analysis steps are conducted on the polarity scores and changes in Bist30 index returns with all the necessary statistical tests. The contribution of our study is that analyzes are made on a daily, weekly and monthly basis. The experimental results show that there are significant positive correlations between the sentiment polarity values and changes in Bist30 index returns for even short-term analysis. As a result, this study points out a useful pathway for the future researches to show that social media posts may convey useful information for financial markets even for short term analysis